Quick-change tooling for fineblanking presses

ABSTRACT

A die set is provided in which the die shoes remain essentially as part of the press and releasably retain interchangeable die members therein. Each die shoe includes locking means supported for generally lateral movement thereon and means for actuating the locking means between a locking position which positively retains a die member within a corresponding cavity in the die shoe and a retracted position which releases the die member for removal from the cavity. Each die shoe also includes ejecting means supported for generally axial movement thereon and means for actuating said ejecting means to eject the die member when the locking means is in its retracted position. The die members are formed with recess means for receiving the locking means.

United States Patent Smith [54] QUICK-CHANGE TOOLING FOR FINEBLANKINGPRESSES [72] Inventor: Roger K. Smith, Enon, Ohio [73] Assignee:International Fineblanking Corporation,

Dayton, Ohio [22] Filed: Jan. 22, 1971 [21] Appl.No.: 108,759

[451 July 4, 1972 Primary Examiner-Charles W. Lanham AssistantExaminer-Gene P. Crosby Attorney-Marechal, Biebel, French & Bugg [57]ABSTRACT A die set is provided in which the die shoes remain essentiallyas part of the press and releasably retain interchangeable die memberstherein. Each die shoe includes locking means supported for generallylateral movement thereon and means for actuating the locking meansbetween a locking position which positively retains a die member withina corresponding cavity in the die shoe and a retracted position whichreleases the die member for removal from the cavity. Each die shoe alsoincludes ejecting means supported for generally axial movement thereonand means for actuating said ejecting means to eject the die member whenthe locking means is in its retracted position. The die members areformed with recess means for receiving the locking means.

15 Claims, 4 Drawing Figures SHEET 10F.2

6 z xwmw P'A'TENTEDJUL 4 m2 INVENTOI? ROGER K. SMITH ATTORNEYSQUICK-CHANGE TOOLING FOR FINEBLANKING PRESSES BACKGROUND OF THEINVENTION .The art of fineblanking requires special die sets and aspecial press. The die sets include die details, such as die members, apunch and punch base, an ejector and backup plate, pressure pins, piercepunch, etc., and all these details are disposed within die shoeshydraulically supported on movable tables located at positions above andbelow a movable strip of metal stock. In the fineblanking pressesdeveloped for the fineblanking process, such as the Osterwalderfineblanking press made in Switzerland by Feintool AG, the lower tableexerts a clamping" force in an upward direction and a second opposing"force is exerted through the upper table in the downward direction.

The clamping and opposing pressures positively clamp the metal stockbetween the ejector and the lower die member for the blanking stroke. Amechanical ram strokes upwardly from the bottom of the press and exertsa blanking" force against a sliding punch disposed within the lower dieshoe. The punch blanks the part into a cavity within the upper diemember but, due to the close tolerance requirements, neither enters nortouches the upper die member.

During the blanking stroke, the punch moves about three times slowerthan in conventional blanking operations, and essentially squeezes themetal into parts having smooth edges, highly accurate contours andholes, and extremely close tolerances. Thus, the primary advantage offineblanked parts is that they do not require additional processing,such as shaving, broaching, coining, reaming or drilling, and the partsare generally ready for use immediately.

Several problems have been encountered with the fineblanking toolingpresently in use. The tooling must be aligned precisely to meet theclose tolerances required, and consequently the die block (upper diemember) and the stripper plate (lower die member) must be rigidlyretained within their respective die shoes. This is generallyaccomplished by bolting or similarly securing the die block and stripperplate directly to their corresponding die shoes.

The problem that results is that the entire die set, including the dieshoes, must be completely dismantled and removed from the press everytime a part must be repaired. This creates considerable down time, onthe order of 1% to 2 hours, because extra care must be taken infastening the parts together in precise alignment. As a result, valuableproduction time is wasted.

Another problem is that parts processors must purchase or build acomplete die set for each different part to be blanked. This creates anexcessively high tooling expense. In fact, because they must purchase orobtain tooling for every order, the initial expense for processors whohave a large number of low quantity orders is almost prohibitive.

SUMMARY OF THE INVENTION The present invention is directed toquick-change tooling for fineblanking presses. In general, the toolingof the present invention provides die shoes which remain essentially aspart of the press and means in the die shoes for releasably retainingdie members therein to facilitate their quick interchangement within thedie shoes. The invention substantially reduces tooling cost, andsubstantially reduces the time required to change tooling in the press.

Generally, the tooling comprises locking means supported for generallylateral movement on each die shoe between a locking position whichpositively retains the corresponding die member within a correspondingcavity in the die shoe and a retracted position which releases the diemember for removal from the cavity. The invention also includes ejectingmeans supported for generally axial movement on each die shoe andpositioned to dislodge the die member from the cavity after the lockingmeans has been moved to its retracted position. Means are provided foractuating the locking means and the ejecting means, and preferablycomprise fluid cylinder means.

In the preferred embodiment, the locking means comprises a pair oflocking pins supported in lateral bores which intersect opposite sidesof the die member cavity. The pins are connected to the fluid cylindermeans preferably disposed within the die shoe, and are received in tightinterfitting engagement within the die members by cooperating recessmeans therein adjacent the lateral bores. The ejecting means comprisesthree axial openings generally radially spaced in the die shoe andconnecting three fluid cylinder means therein with the die membercavity. An ejecting rod is positioned within each opening and isactuated in the axial direction by the fluid cylinder means to lift anddislodge or eject the die member from the cavity so that it may bequickly removed and replaced with another die member. The latter diemember is then locked within the cavity by the locking means for thenext blanking operation.

The cooperating recess means in the tapered mating surface of each diemember preferably includes a pair of chord-like slots on diametricallyopposite sides of the tapered peripheral surface of the die memberadjacent to and genei'ally aligned with the bores in the die shoe. Theslots define internal surfaces which are preferably formed to receivethe locking pins in tight interfitting engagement for positivelyretaining the die members within the cavity and for providing lateralstability.

The invention enables the part processor to purchase a single set of dieshoes and to maintain a series of interchangeable die members and otherdetails for processing parts with a number of difierent configurations.The processor is accordingly not forced to purchase die shoes every timehe purchases a tool, and therefore the invention provides a considerablesavings in tooling costs. In addition, the invention enables theprocessor to reduce down time for interchanging tooling, therebyaffording a considerable increase in efiiciency. Hence, the tooling ofthe present invention, from the practical standpoint, is a significantadvance in the fineblanking art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of afineblanking press, partially broken away, and showing the tooling ofthe present invention mounted therein;

FIG. 2 is an axial vertical sectional view of a die set mounted on upperand lower tables of the press and constructed according to the presentinvention, the tables being partially broken away;

FIG. 3 is a top view of a die shoe and die member taken along line 33 inFIG. 2; and

FIG. 4 is a fragmentary sectional view taken along line 4-4 in FIG. 3and showing a locking pin disposed within a slot in the die member andwithin a support bearing within a lateral bore in the die shoe.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, afineblanking press 10, such as the type manufactured by Feintool AG ofSwitzerland and known as the Osterwalder press, includes a cast pressframe 11 consisting of a lower housing 12 and an upper housing 13connected by a pair of integral left-hand columns 14 and a pair ofintegral right-hand columns 15, and defining a central working chamber16 therebetween. Strip stock S from a coil (not shown) is conveyedhorizontally between the columns and through the chamber 16 by anautomatic infeed unit 17 and by a cooperating automatic outfeed unit 18,slidably mounted on the left and right-hand columns respectively.

The press 10 also includes lower and upper tables 20 and 21 each ofwhich is supported for reciprocating axial or vertical movement byhydraulic actuating units (not shown) mounted within the lower and upperhousings I2 and 13. The strip stock S is blanked into parts by a die setwhich includes lower and upper die shoes 22 and 23 mounted on the lowerand upper tables 20 and 21 respectively. A tapered preferablyfrusto-conical cavity 25 is formed within each die shoe and extends inthe vertical or axial direction, and a mating tapered die member orstripper plate 26 is disposed within the lower cavity 25, and a matingtapered die member or die block 27 is disposed within the upper cavity25. As shown in FIG. 4, the degree of taper of the cavities and matingdie members is with full vertical for facilitating removal of the diemembers from the die shoes, as described hereinafter. Both die membetsare formed with axial bores or cavities 28 having configurationscorresponding to the configuration of the part being blanked. Forsimplicity, the configurations of the cavities 28 are shown as beingcircular. In accordance with fineblanking practice, a vee-ring 30 isintegrally formed on the upper surface of the stripper plate 26 aroundthe outer periphery of the cavity 28 for gripping the strip stock S.

The hydraulic units move the die members 26 and 27 between an openposition for advancing or feeding the strip stock S therebetween and aclosed position for clamping and gripping the strip stock S, and, inaccordance with general practice a pair of guide assemblies 32consisting of ball cages, pins, and bearings maintain the die shoes inalignment. Clamping results from a clamping force exerted in the upwarddirection against die member 26 by the lower hydraulic unit and a secondopposing" force exerted in the downward direction against the ejector 40within the die block by the upper hydraulic unit, and these forces areasserted and reasserted during and after the blanking stroke.

A punch 33 is slidably mounted within the lower cavity 28 and issupported by a base 34 slidably disposed within a cylindrical cavity orbore 35 formed in the lower die shoe 22 concentric with the cavity 25.The base 34 seats on an adapter ring 37 recessed within the lower table20 and is connected to a ram 38 by means of a draw bar 39. After thestock is clamped, a third mechanically operated unit (not shown) withinthe lower housing 12 actuates die ram 38 to exert a blanking" force onthe punch base 34 which overrides the opposing pressure acting againstthe ejector 40 and displaces the punch 33 upwardly within the stripperplate 26, thereby blanking the part from the strip stock S upwardly intothe cavity 28 within the die block 27.

The blanked part is punched or blanked against the slidable ejector 40within the cavity 28 and having an outer configuration corresponding tothat of the punch 33. As shown in FIG. 2, a pierce punch holder 41 and aback-up plate 42 are slidably disposed within a cylindrical cavity orbore 43 formed in the die shoe 23 above the die block 27, and areconnected by a dowel pin 49 and are bolted to the die block 27 by bolts44 to form a unit which is disposed within the die shoe 23. A piercepunch 45 extends through the ejector 40 and seats against the back-upplate 42. Simultaneously with the blanking of the part, the pierce punch45 punches a slug out of the blanked part into a center hole formedwithin the punch 33 against an ejector pin 46 supported by an ejectorbridge piece received within the base 34 and mounted on pressure pinsseated on the adapter ring 37.

When the die members 26 and 27 separate and the blanking force isreleased, the clamping and opposing pressures are reasserted between theejector 40 and the punch 33, and the ejector 40 ejects the blanked partfrom the die block 27 and the ejector pin 46 ejects the slug from thepunch 33. After the part and slugs are removed, usually with air, thedie set is ready for the next blanking operation.

In accordance with the present invention, each die shoe has a pair ofbores 47 which extend laterally therethrough and tangentially intersectdiametrically opposite sides of the corresponding tapered cavity 25. Acylindrical locking pin 48 is received within each bore 47 and issupported therein for reciprocating movement by an elongated cylindricalbearing 50 tangentially intersecting the tapered cavity 25 and by ashort cylindrical guide bearing 51 adjacent the outer end of therespective bore 46. The locking pins preferably have circularcross-sections, rather than square cross-sections, for example, becausecomers and other sharp surfaces are susceptible to breakage understresses encountered in blanking and ejecting. The bearings 50 and 51are press fitted within the bores, and, as shown in FIG. 4, bearing hasan arcuate notch 52 therein which conforms the adjacent portion thereofto the tapered contour of the cavity 25.

In the preferred embodiment, the locking pins 48 are actuated bydouble-acting fluid cylinder means 54 including a piston 55 mounted onan elongated piston rod 58 and slidably disposed within a cylindricalbore 60 formed within the die shoe and extending into a cup-like end cap61 secured to the die shoe by a series of bolts 62. The cap 61 is sealedto the die shoe by a gasket 63 confined within a counterbore 64 formedwithin the outer end of the cavity 60 for receiving an interfitting lip65 of the cap 61. The piston rod 58 extends through an opening 66 in theend cap 61, and Orings form seals between the rod 58 and the opening 66and between the piston 55 and the bore 60.

The locking pins 48 within each die shoe are rigidly connected to thecorresponding piston rod 58 by a connecting plate 67 which has suitableholes for receiving the outer end portions of the locking pins 48 andpiston rod 58. The plate 67 is tightened by lock nuts 69.

The cylinders or bores 54 are connected to a hydraulic fluid supply (notshown) preferably through a suitable four-way flow control valve, forpurposes more fully apparent hereafter, and hydraulic fluid underpressure is delivered alternately to ports 70 in the end caps 61 toextend the rods 58 in a left-toright direction, and then to ports 71through lines 72 in the die shoes to retract the rods 58 in aright-to-left direction. The connection plates 67 transmit thisreciprocal movement to the locking pins 48, so that the pins extend intothe cavities 25 when the rods 58 are moved to the right (shown in dottedlines to the right of notch 52) and retract out of the cavities 25 whenthe rods are moved to the left, (shown in dotted lines to the left ofnotch 52). It should be apparent that other actuating means could alsobe used, such as pneumatically actuated cylinders or the like.

To accomodate the locking pins 48, each of the die members 26 and 27 hasrecess means preferably defining a pair of laterally extending slots 74in diametrically opposite tapered side surfaces thereof defininginternal surfaces therein which are curved for receiving the cylindricallocking pins 48. Each die member is also preferably formed with an axialslot 75 (FIG, 3) which cooperates with an axially extending bore 76 inthe die shoe to receive an axial dowel pin 77. The dowel pin 77 locatesthe die members in the cavities 25 and prevents them from rotatingtherein, in the same manner that dowel pins 77' locate the punch base 34within the lower bore 36 and the pierce punch plate 41 and backup plate42 within the upper bore 43.

As shown in FIG. 3, the slots 74 are adjacent to and aligned with theinternal surface of the adjacent support bearing 50, so that the outersurfaces of the locking pins 48 mate against the curved surfaces thereofin tight interfitting engagement. In this preferred form, the slots 74define chords in the tapered frusto-conical surfaces of the die members,and the curved surfaces of the slots 74 mate against and support thepins 48 along the entire length of these chords to provide lateralstability. This form is thus preferred over the alternate form ofcircumferential slots in the peripheral surfaces of the die members,because in the latter form the curved surface of the slot would mateagainst and support the locking pins at only two points, the tangentialpoints of contact with the locking pins, and the slots would not providethe desired lateral stability.

In addition, in accordance with the present invention, each die shoe 22and 23 also includes means for ejecting the die members 26 and 27 tofacilitate quick interchangement thereof. The preferred embodimentincludes a series of three double acting fluid cylinder means 78 spacedat 120 intervals around the periphery of the lower cavity 36. Each fluidcylinder means 78 is similar in construction to the fluid cylinder means54 and includes a piston 80 mounted on an elongated piston rod 82 andslidably disposed within a cylindrical bore 83 formed within the dieshoe. The bore 83 is sealed by a gasket 85 confined within a counterbore86 formed within the outer end of the bore 83 by plug member 87connected to the die shoe. The piston rods 82 are disposed withincylindrical openings 88 connecting the bores 83 with the cavities 25,and are preferably flush with the internal shoulders 36 when the pistons80 are in the retracted position shown in FIG. 2. O-rings form sealsbetween the rods 82 and the openings 88 and between the pistons 80 andthe bores 83.

As in the case of the fluid cylinder means 54, the fluid cylinder means78 are connected to a hydraulic fluid supply (not shown), as by asuitable reversible flow control valve or the like, and hydraulic fluidis delivered alternately to upper manifolds 90 and then to lowermanifolds 91 in the die shoes at the opposite ends thereof from thefluid cylinder means 54. The manifolds 90 and 91 distribute the fluidthrough upper passages 93 and lower passages 94 in the die shoes toupper ports 95 and lower ports 96 to the bores 83. When delivered to thelower ports 96, the fluid moves the piston rods 82 upwardly to lift anddislodge or eject the die members 26 and 27 for quick interchangement.Conversely, when delivered to the upper ports 96, the fluid retracts therods 82 within the openings 88 for insertion of die members into thecavities 25.

In operation, a suitable four way valve (not shown) connects the outerand inner ports 70 and 71 of the fluid cylinder means 54 and the upperand lower ports 95 and 96 to the fluid cylinder means 78 to a source ofpressurized hydraulic fluid. When it is desired to interchange the diemembers 26 and 27 with different die members for forming parts ofdifferent configuration, the following procedure is followed.

First, the operator switches the four way valve to connect the sourcewith ports 71, and the hydraulic fluid urges the rods 58 fromright-to-left to retract the pins 48 and release the die members 26 and27. The valve is then moved to connect the source of hydraulic fluidwith the lower ports 96, and the hydraulic fluid actuates the rods 82upwardly into the cavities 25 to dislodge and release the die members 26and 27 from tight interfitting engagement with the cavities 25. Thetaper of 5 with full vertical facilitates dislodgement.

The die members 26 and 27 are then removed from the cavities 25, and thevalve is moved to connect the source of hydraulic fluid with ports 95causing the fluid to retract the piston rods 82 within the openings 88.The punch 34 and the ejector 40 are then replaced with a correspondingpunch and ejector having the configuration of the next part to beblanked.

The new pair of mating tapered die members having cavities 28corresponding to the configurations of the new punch and ejector, andhaving identical slots 74 and 75 therein, are then located within thecavities 25. In the final step before blanking can begin, the valve ismoved to connect the fluid supply to ports 70, and the fluid actuatesthe rods 58 from left-to-right to extend the locking pins 48 into andthrough the slots 74 in the new die members where they are received bythe elongated bearings 50, thereby providing lateral stability. Movementof the locking pins 48 through the slots 74 produces a bighting pressurein the downward direction which presses the die members downwardlyagainst the internal shoulders 36 of the bores 25 to insure properalignment and to restrain the die members from moving under theinfluence of high pressures in subsequent blanking and ejectingoperations. In all, only about l0 minutes is required to complete theforegoing interchanging operation.

It is thus apparent from the foregoing description and accompanyingdrawing that die sets constructed according to the present inventionprovide desirable features and ad vantages. For example, the die shoesbecome essentially an in tegral part of the press, and enable the partsprocessor to purchase and accumulate a series of interchangable diemembers. Thus the processor does not have to buy die shoes every time hebuys a tool. This not only reduces the initial and overall tooling cost,but also reduces the part cost to the customer.

Another important advantage of the invention is the savings in down timewhich results when the die shoes do not require changing. As pointed outabove, to change the die members and their corresponding punches andejectors requires only about ten minutes, while in previous practice achange accomplishing the same result required as must as a full 1% to 2hours.

In addition, the quick-change tooling of the present invention enablesthe processor to make efficient use of his machines. For example, if aparticular die member or its details should become damaged, theprocessor can produce another part while the damaged part is beingrepaired by simply installing a second set of die members. In addition,the processor may advantageously install sets of die shoes of varyingsize in different size presses and thereby improve his overallefficiency and flexibility.

Another feature of the invention is that the fluid cylinder means arelocated within the die shoes, and consequently there are no outsideforces to upset the alignment. Also, contrary to previous practice, thestinger plate is essentially a free unit because it is not bolted to itscorresponding die shoe, while the die block, instead of being bolted toits corresponding die shoe, is bolted to the piercing punch holder andthe backup plate and these parts are removable from the die shoe as aunit.

While the forms of apparatus herein described constitutes preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing from the scope of the invention.

What is claimed is:

1. In a die set including upper and lower die shoes each having meansdefining a tapered cavity, a mating tapered die member disposed withineach said cavity, and means supporting said die shoes for relativereciprocating axial movement of said die members between an openposition for receiving strip material therebetween and a closed positionfor blanking parts from the strip material, the improvement forretaining and releasing each said die member within the correspondingsaid die shoe cavity, comprising locking means supported for generallylateral movement on each said die shoe between a locking positionpositively retaining the corresponding said die member within thecorresponding said cavity and a retracted position releasing said diemember for removal from said cavity, ejecting means supported forgenerally axial movement on each said die shoe and positioned to releasethe corresponding said die member from the corresponding said cavitywhen said locking means is in said retracted position, and means foractuating said locking means and said ejecting means to facilitate quickinterchangement of said die members within said die shoes.

2. The die set defined in claim 1 wherein said actuating means comprisesfluid cylinder means for said locking means and fluid cylinder means forsaid ejecting means.

3. In a die set for a fineblanking press having upper and lower dieshoes each having means defining a cavity, a die member disposed withineach said die shoe cavity in tightfitting relation, each said die memberhaving an opening corresponding in shape to the part to be blanked, apunch member slidably disposed within at least one of said openings,means supporting said die shoes for relative reciprocating axialmovement of said die members between an open position for receivingstrip material therebetween and a closed position gripping the material,and means for moving said punch member within the corresponding saidopening after said die members have moved to said closed position forblanking parts from the strip material, an improved means for retainingat least one of said die members within the corresponding said die shoecavity, comprising locking means supported for generally lateralmovement within said die shoe between a locking position positivelyretaining said die member within said cavity and a retracted position,means on said die shoe for actuating said locking means to release saiddie member for removal from said cavity, ejecting means offset laterallyfrom the center of said cavity and supported for generally axialmovement within said die shoe and positioned to press said die memberfrom said cavity when said locking means is released, and means on saiddie shoe for actuating said ejecting means to facilitate quickinterchangement of said die member within said die shoe.

4 The die set defined in claim 3 wherein said locking means comprises apair of parallel bores extending laterally within said die shoe andintersecting diametrically opposite sides of said cavity, recess meansin diametrically opposite sides of said die member and generallyadjacent to and aligned with said bores, a pair of locking pins disposedwithin said bores, means connecting said actuating means to said lockingpins, and said actuating means being operative to move said locking pinsbetween a locking position within said recess means in tightinterfitting engagement with said die member and a retracted positionremoved from said recess means in said die member.

5. The die set defined in claim 4 wherein said bores have circularcross-sections, wherein said pins have circular cross-sections, andwherein said recess means in said die members are comprise parallelslots for receiving said circular pins and for providing lateralstability.

6. The die set defined in claim 4 including bearing means positionedwithin each said bore adjacent said cavity for receiving and supportingsaid pins when in their locking positrons.

7. The die set defined in claim 3 wherein said actuating means comprisesfluid cylinder means, and said fluid cylinder means includes acylindrical bore in said die shoe which defines a circular openingtherein, means forming an end cap connected to said die shoe at saidopening and having a hole therein concentric with said opening, a pistonrod in said bore extending through said hole in said cap, and a pistonwithin said bore and mounted on said piston rod.

8. The die set defined in claim 3 including pin means extending axiallywithin each said die member and the corresponding said die shoe forprecisely orientating said die member within the corresponding saidcavity.

9. The die set defined in claim 7 wherein said connecting meanscomprises a plate outboard of said die shoe and having holes therein forreceiving said piston rod and said locking pins, and means for securingsaid piston rod and said locking pins to said plate.

10. In a die set including upper and lower die shoes each having meansdefining a tapered cavity, a mating tapered die member disposed withineach said cavity, and means supporting said die shoes for relativereciprocating axial movement of said die members between an openposition for receiving strip material therebetween and a closed positionfor blanking parts from the strip material, the improvement forretaining and releasing at least one of said die members from acorresponding said cavity, comprising means for locking said die memberwithin said cavity, ejecting means supported for generally axialmovement within said die shoe and positioned to move said die memberwithin said cavity when said locking means is released, and means onsaid die shoe for actuating said ejecting means to facilitate quickremoval of said die member from said die shoe.

11. The die set defined in claim 10 wherein said actuating meanscomprises fluid cylinder means, and said fluid cylinder means includes aplurality of axially extending bores in said die shoe, means for closingsaid bores within said die shoes, piston rods extending through saidbores, and pistons disposed within said bores and mounted on said pistonrods.

12. The die set defined in claim 11 wherein three of said bores andcorresponding said pistons are uniformly spaced within said shoe.

13. In a die set for use in a fineblanking press and including upper andlower die shoes each having means defining an upper tapered cavity and alower cylindrical cavity, a mating tapered die member dis sed withineach said tapered cavity, a sliding punch assemb y disposed within saidlower cylindncal cavity of said lower die shoe, means supporting saiddie shoes within said machine for relative reciprocating axial movementof said die members between an open position for receiving stripmaterial therebetween and a closed position for clamping said stripmaterial therebetween, and ram means for actuating said punch assemblyto blank parts from said clamped material, the improvement for retainingand releasing at least one said die members within the correspondingsaid die shoe cavity, comprising a pair of bores extending laterally inat least one said die shoe and intersecting said tapered cavity thereinon diametrically opposite sides thereof, a locking pin disposed withineach said bore, recess means in diametrically opposite sides of said diemember and having curved surfaces adjacent to and aligned with saidbores in said die shoe, means extending laterally within said die shoefor actuating said pins within said bores, said actuating means beingeffective to move said pins between a locking position within saidrecess means in said die member for positively retaining said die memberwithin its corresponding said cavity and retracted position releasingsaid die member from said cavity, openings extending axially in said dieshoe and communicating with said tapered cavity, ejecting membersdisposed within said openings, and means within said die shoe foractuating said ejecting members to lift and eject said die member insaid tapered cavity when said locking pins are in their retractedposition to facilitate quick interchangement of said die member withinsaid die shoes.

14. In a die set for blanking parts in a fineblanking press having upperand lower die shoes, each said die shoe including means defining anupper tapered cavity and a lower cylindrical cavity therein, acooperating punch member for each die shoe each having the configurationof the part being punched, a pair of bores extending laterally in atleast one said die shoe and intersecting said tapered cavity thereingenerally tangentially on diametrically opposite sides thereof, alocking pin slidably disposed within each said bore, and means on saiddie shoe for actuating said pins within said bores between an extendedposition within the corresponding said cavity and a retracted positionremoved from said cavity, an improved die member adapted for quickinterchangement within each of said die shoes and including a taperedsurface for mating with the corresponding tapered cavity, an axialcavity having the configuration of the part being blanked for receivingone of said cooperating punch members of the same configuration, andrecess means on said tapered surface in lateral alignment with saidbores for receiving said locking pins when they are actuated to theirextended position, said recess means being formed for receiving saidpins in tight mating engagement for retaining said die member withinsaid cavity and for maintaining the alignment of said punch membersduring blanking.

15. The die set defined in claim 14 wherein said recess means comprisesa pair of parallel slots arranged in diametrically opposite relationwithin said tapered surface for receiving said pins in tight matingengagement therealong to provide lateral stability during blanking.

1. In a die set including upper and lower die shoes each having meansdefining a tapered cavity, a mating tapered die member disposed withineach said cavity, and means supporting said die shoes for relativereciprocating axial movement of said die members between an openposition for receiving strip material therebetween and a closed positionfor blanking parts from the strip material, the improvement forretaining and releasing each said die member within the correspondingsaid die shoe cavity, comprising locking means supported for generallylateral movement on each said die shoe between a locking positionpositively retaining the corresponding said die member within thecorresponding said cavity and a retracted position releasing said diemember for removal from said cavity, ejecting means supported forgenerally axial movement on each said die shoe and positioned to releasethe corresponding said die member from the corresponding said cavitywhen said locking means is in said retracted position, and means foractuating said locking means and said ejecting means to facilitate quickinterchangement of said die members within said die shoes.
 2. The dieset defined in claim 1 wherein said actuating means comprises fluidcylinder means for said locking means and fluid cylinder means for saidejecting means.
 3. In a die set for a fineblanking press having upperand lower die shoes each having means defining a cavity, a die memberdisposed within each said die shoe cavity in tight-fitting relation,each said die member having an opening corresponding in shape to thepart to be blanked, a punch member slidably disposed within at least oneof said openings, means supporting said die shoes for relativereciprocating axial movement of said die members between an openposition for receiving strip material therebetween and a closed positiongripping the material, and means for moving said punch member within thecorresponding said opening after said die members have moved to saidclosed position for blanking parts from the strip material, an improvedmeans for retaining at least one of said die members within thecorresponding said die shoe cavity, comprising locking means supportedfor generally lateral movement within said die shoe between a lockingposition positively retaining said die member within said cavity and aretracted position, means on said die shoe for actuating said lockingmeans to release said die member for removal from said cavity, ejectingmeans offset laterally from the center of said cavity and supported forgenerally axial movement within said die shoe and positioned to presssaid die member from said cavity when said locking means is released,and means on said die shoe for actuating said ejecting means tofacilitate quick interchangement of said die member within said dieshoe.
 4. The die set defined in claim 3 wherein said locking meanscomprises a pair of parallel bores extending laterally within said dieshoe and intersecting diametrically opposite sides of said cavity,recess means in diametrically opposite sides of said die member andgenerally adjacent to and aligned with said bores, a pair of lockingpins disposed within said bores, means connecting said actuating meansto said locking pins, and said actuating means being operative to movesaid locking pins between a locking position within said recess means intight interfitting engagement with said die member and a retractedposition removed from said recess means in said die member.
 5. The dieset defined in claim 4 wherein said bores have circular cross-sections,wherein said pins have circular cross-sections, and wherein said recessmeans in said die members are comprise parallel slots for receiving saidcircular pins and for providing lateral stability.
 6. The die setdefined in claim 4 incluDing bearing means positioned within each saidbore adjacent said cavity for receiving and supporting said pins when intheir locking positions.
 7. The die set defined in claim 3 wherein saidactuating means comprises fluid cylinder means, and said fluid cylindermeans includes a cylindrical bore in said die shoe which defines acircular opening therein, means forming an end cap connected to said dieshoe at said opening and having a hole therein concentric with saidopening, a piston rod in said bore extending through said hole in saidcap, and a piston within said bore and mounted on said piston rod. 8.The die set defined in claim 3 including pin means extending axiallywithin each said die member and the corresponding said die shoe forprecisely orientating said die member within the corresponding saidcavity.
 9. The die set defined in claim 7 wherein said connecting meanscomprises a plate outboard of said die shoe and having holes therein forreceiving said piston rod and said locking pins, and means for securingsaid piston rod and said locking pins to said plate.
 10. In a die setincluding upper and lower die shoes each having means defining a taperedcavity, a mating tapered die member disposed within each said cavity,and means supporting said die shoes for relative reciprocating axialmovement of said die members between an open position for receivingstrip material therebetween and a closed position for blanking partsfrom the strip material, the improvement for retaining and releasing atleast one of said die members from a corresponding said cavity,comprising means for locking said die member within said cavity,ejecting means supported for generally axial movement within said dieshoe and positioned to move said die member within said cavity when saidlocking means is released, and means on said die shoe for actuating saidejecting means to facilitate quick removal of said die member from saiddie shoe.
 11. The die set defined in claim 10 wherein said actuatingmeans comprises fluid cylinder means, and said fluid cylinder meansincludes a plurality of axially extending bores in said die shoe, meansfor closing said bores within said die shoes, piston rods extendingthrough said bores, and pistons disposed within said bores and mountedon said piston rods.
 12. The die set defined in claim 11 wherein threeof said bores and corresponding said pistons are uniformly spaced withinsaid shoe.
 13. In a die set for use in a fineblanking press andincluding upper and lower die shoes each having means defining an uppertapered cavity and a lower cylindrical cavity, a mating tapered diemember disposed within each said tapered cavity, a sliding punchassembly disposed within said lower cylindrical cavity of said lower dieshoe, means supporting said die shoes within said machine for relativereciprocating axial movement of said die members between an openposition for receiving strip material therebetween and a closed positionfor clamping said strip material therebetween, and ram means foractuating said punch assembly to blank parts from said clamped material,the improvement for retaining and releasing at least one said diemembers within the corresponding said die shoe cavity, comprising a pairof bores extending laterally in at least one said die shoe andintersecting said tapered cavity therein on diametrically opposite sidesthereof, a locking pin disposed within each said bore, recess means indiametrically opposite sides of said die member and having curvedsurfaces adjacent to and aligned with said bores in said die shoe, meansextending laterally within said die shoe for actuating said pins withinsaid bores, said actuating means being effective to move said pinsbetween a locking position within said recess means in said die memberfor positively retaining said die member within its corresponding saidcavity and retracted position releasing said die member from saidcavity, openings extending axially in said die shoe and communicatingwiTh said tapered cavity, ejecting members disposed within saidopenings, and means within said die shoe for actuating said ejectingmembers to lift and eject said die member in said tapered cavity whensaid locking pins are in their retracted position to facilitate quickinterchangement of said die member within said die shoes.
 14. In a dieset for blanking parts in a fineblanking press having upper and lowerdie shoes, each said die shoe including means defining an upper taperedcavity and a lower cylindrical cavity therein, a cooperating punchmember for each die shoe each having the configuration of the part beingpunched, a pair of bores extending laterally in at least one said dieshoe and intersecting said tapered cavity therein generally tangentiallyon diametrically opposite sides thereof, a locking pin slidably disposedwithin each said bore, and means on said die shoe for actuating saidpins within said bores between an extended position within thecorresponding said cavity and a retracted position removed from saidcavity, an improved die member adapted for quick interchangement withineach of said die shoes and including a tapered surface for mating withthe corresponding tapered cavity, an axial cavity having theconfiguration of the part being blanked for receiving one of saidcooperating punch members of the same configuration, and recess means onsaid tapered surface in lateral alignment with said bores for receivingsaid locking pins when they are actuated to their extended position,said recess means being formed for receiving said pins in tight matingengagement for retaining said die member within said cavity and formaintaining the alignment of said punch members during blanking.
 15. Thedie set defined in claim 14 wherein said recess means comprises a pairof parallel slots arranged in diametrically opposite relation withinsaid tapered surface for receiving said pins in tight mating engagementtherealong to provide lateral stability during blanking.